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Areviewandanalysisofcurrentcomputer-aidedfixturedesignapproachesIainBoyle,YimingRong,DavidC.BrownKeywords:Computer-aidedfixturedesignFixturedesignFixtureplanningFixtureverificationSetupplanningUnitdesignABSTRACTAkeycharacteristicofthemodernmarketplaceistheconsumerdemandforvariety.Torespondeffectivelytothisdemand,manufacturersneedtoensurethattheirmanufacturingpracticesaresufficientlyflexibletoallowthemtoachieverapidproductdevelopment.Fixturing,whichinvolvesusingfixturestosecureworkpiecesduringmachiningsothattheycanbetransformedintopartsthatmeetrequireddesignspecifications,isasignificantcontributingfactortowardsachievingmanufacturingflexibility.Toenableflexiblefixturing,considerablelevelsofresearchefforthavebeendevotedtosupportingtheprocessoffixturedesignthroughthedevelopmentofcomputer-aidedfixturedesign(CAFD)toolsandapproaches.Thispapercontainsareviewoftheseresearchefforts.Overseventy-fiveCAFDtoolsandapproachesarereviewedintermsofthefixturedesignphasestheysupportandtheunderlyingtechnologyuponwhichtheyarebased.Theprimaryconclusionofthereviewisthatwhilesignificantadvanceshavebeenmadeinsupportingfixturedesign,thereareprimarilytworesearchissuesthatrequirefurthereffort.ThefirstoftheseisthatcurrentCAFDresearchissegmentedinnatureandthereremainsaneedtoprovidemorecohesivefixturedesignsupport.Secondly,agreaterfocusisrequiredonsupportingthedetaileddesignofafixture’sphysicalstructure.2010ElsevierLtd.Allrightsreserved.Contents1.Introduction………………………………………………………………………………………22.Fixturedesign…………………………………………………………………………………….23.CurrentCAFDapproaches……………………………………………………………………….43.1Setupplanning…………………………………………………………………………….43.1.1Approachestosetupplanning……………………………………………………...43.2Fixtureplanning…………………………………………………………………………..43.2.1Approachestodefiningthefixturingrequirement…………………………………63.2.2Approachestonon-optimizedlayoutplanning…………………………………….63.2.3Approachestolayoutplanningoptimization………………………………………63.3Unitdesign………………………………………………………………………………...73.3.1Approachestoconceptualunitdesign……………………………………………..73.3.2Approachestodetailedunitdesign………………………………………………...73.4Verification………………………………………………………………………………..83.4.1Approachestoconstrainingrequirementsverification…………………………….83.4.2Approachestotolerancerequirementsverification………………………………..83.4.3Approachestocollisiondetectionrequirementsverification………………………83.4.4Approachestousabilityandaffordabilityrequirementsverification………………93.5Representationoffixturinginformation…………………………………………………..94.AnanalysisofCAFDresearch…………………………………………………………………...94.1ThesegmentednatureofCAFDresearch………………………………………………...94.2Effectivelysupportingunitdesign………………………………………………………104.3Comprehensivelyformulatingthefixturingrequirement………………………………..104.4ValidatingCAFDresearchoutputs……………………………………………………....105.Conclusion…………………………………………………………………………………...…10References…………………………………………………………………………………………101.IntroductionAkeyconcernformanufacturingcompaniesisdevelopingtheabilitytodesignandproduceavarietyofhighqualityproductswithinshorttimeframes.Quickreleaseofanewproductintothemarketplace,aheadofanycompetitors,isacrucialfactorinbeingabletosecureahigherpercentageofthemarketplaceandincreasedprofitmargin.Asaresultoftheconsumerdesireforvariety,batchproductionofproductsisnowmorethenormthanmassproduction,whichhasresultedintheneedformanufacturerstodevelopflexiblemanufacturingpracticestoachievearapidturnaroundinproductdevelopment.Anumberoffactorscontributetoanorganization’sabilitytoachieveflexiblemanufacturing,oneofwhichistheuseoffixturesduringproductioninwhichworkpiecesgothroughanumberofmachiningoperationstoproduceindividualpartswhicharesubsequentlyassembledintoproducts.Fixturesareusedtorapidly,accurately,andsecurelypositionworkpiecesduringmachiningsuchthatallmachinedpartsfallwithinthedesignspecificationsforthatpart.Thisaccuracyfacilitatestheinterchangeabilityofpartsthatisprevalentinmuchofmodernmanufacturingwheremanydifferentproductsfeaturecommonparts.Thecostsassociatedwithfixturingcanaccountfor10–20%ofthetotalcostofamanufacturingsystem[1].Thesecostsrelatenotonlytofixturemanufacture,assembly,andoperation,butalsototheirdesign.Hencetherearesignificantbenefitstobereapedbyreducingthedesigncostsassociatedwithfixturingandtwoapproacheshavebeenadoptedinpursuitofthisaim.Onehasconcentratedondevelopingflexiblefixturingsystems,suchastheuseofphase-changingmaterialstoholdworkpiecesinplace[2]andthedevelopmentofcommercialmodularfixturesystems.However,thesignificantlimitationoftheflexiblefixturingmantraisthatitdoesnotaddressthedifficultyofdesigningfixtures.Tocombatthisproblem,asecondresearchapproachhasbeentodevelopcomputer-aidedfixturedesign(CAFD)systemsthatsupportandsimplifythefixturedesignprocessanditisthisresearchthatisreviewedwithinthispaper.Section2describestheprincipalphasesofandthewidevarietyofrequirementsdrivingthefixturedesignprocess.SubsequentlyinSection3anoverviewofresearcheffortsthathavefocuseduponthedevelopmentoftechniquesandtoolsforsupportingtheseindividualphasesofthedesignprocessisprovided.Section4critiquestheseeffortstoidenti